“And out of the end of his wand burst, not a shapeless cloud of mist, but a blinding, dazzling, silver animal.”

This is the physical description of the Patronus charm, a defensive magic of extraordinary nature, being casted by one of the most renowned protagonists in the modern fantasy genre, Harry Potter.

The fantastic wizarding universe of Harry Potter has captivated millions of readers around the world with its bountiful array of fascinating magic. Among them, the Patronus charm, which summons a corporeal spirit guardian for protection against the dementors—the creatures that feed on human happiness—, ranks on the top of the table.

This spell somehow feels more vivid as life resonates within us. There seems to be some true inherent magic which attaches this spell to the readers, soul to soul. The secret element, which enables this spell to transcend the boundaries of fantasy, was no other than the author J.K Rowling’s genuine life experience—she invented this idea while she was battling clinical depression and the essence of truth her soul bled through the struggle, sank within her writing.

In order to cast the spell, one must think of a memory and, quoted from Rowling’s writing, “not just any memory, a very happy memory, a very powerful memory.” While recalling the happiest memory for us would not summon any mystic shapes of animals jovially leaping around the room, the product could still be as powerful as that of the fictional spell.

Nostalgia, which refers to a sentimental longing for past, could exert numerous positive impacts on a person—from improving mood, strengthening positive self-esteem, to even providing existential meaning. While the whirlpool of intense emotions accompanying the process could sometimes be overwhelming, recollection of the past could be a piece of magic in real life, perhaps the only one, which could be performed to withstand the crawling depression.

The most popular symbol of nostalgia seems to be the stars. The symbolism of stars to create a sense of nostalgia has always been the favorite device to be employed in all artistic mediums. It is not difficult to encounter the stars serving as the source of reminiscence in recent popular media of books, music and movies.

Now, the reason why the symbol of stars appeals to people the most remains elusive.

There are endless possible explanations, but perhaps it is because to adults, childhood is like a sky full of stars. It was when the stars were windows to their dreams; when they were able to hear the playful whispers of the sky; when they believed that friendships would last forever. When all of us were honest and not afraid to open our minds to others. People miss the time they naively dreamed and wondered about the world. One day they may gaze at the night sky and realize how stationary their celestial friends have remained. They are awed and aggrieved at the same time as change has overwhelmed their lives. Childhood was the period when our hearts could perceive the “invisible”—something that only resonates with innocence—which the majority of the adults can no longer discern.

Now we must not confuse ourselves. Growing up is not the problem; in fact, it is an inevitable process. The true change begins not from gaining more knowledge but forgetting.

The force of oblivion insidiously swallows the innocence in one’s heart and even forces one to neglect his or her identity. Amid countless piles of homework, endlessly shifting social circles, and daunting uncertainty about the future, people forget the children they once were. As one’s sight narrows down to what one can see with the eyes, the mind naturally fails to generate hope, an emotion which is summoned through the visualization of love, the mechanism of the Patronus charm previously stated. The inaptitude to produce hope significantly increases one’s emotional vulnerability to solitude and depression, which can result in severe levels of pain, anguish and distress.

The solution is to resist the ceaselessly approaching clutches of oblivion by conjuring hope from “the happiest memory” of your life. Accept the slight ache of yearning which comes with it as the wistfulness reminds us of the true value of a moment. If one learns to savor the bittersweet flavor, one shall have the courage to advance forward into the uncharted realm of the future.

Let us stargaze. Let our imagination wander and wonder. Climb the stairs of stars and follow the Milky Way, to reach the place where no present-day forgetfulness can haunt us.

So now as our beloved Professor Lupin instructs, “Close your eyes. Concentrate and explore your past. Have the memory? Allow it to fill you up. Lose yourself in it. Then speak the incantation: Expecto Patronum. Very good. Now, shall we? Wands ready.”